S000003867 [Member] Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| BlackRock Capital Appreciation Portfolio | BlackRock Capital Appreciation Portfolio | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 12.04% | 31.49% | 49.60% | (37.59%) | 21.22% | 40.16% | 32.79% | 2.42% | 33.62% | 0.40% |